Differences between Amphibian and Reptile
Contents
Differences between Amphibian and Reptile
Amphibians and reptiles are two distinct classes of vertebrate animals.[1] While both are ectothermic, meaning they rely on the external environment to regulate their body temperature, they exhibit significant differences in their skin, reproduction, development, and physiology.[2][3][4] Reptiles evolved from amphibians approximately 300 million years ago, developing key adaptations that allowed for a fully terrestrial existence.[5]
Comparison Table
| Category | Amphibian | Reptile |
|---|---|---|
| Skin | Smooth, moist, and permeable without scales.[1] | Dry and covered in scales made of keratin.[1] |
| Respiration | Lungs, skin, and gills (in larval stage).[3] | Lungs only.[3] |
| Eggs | Gelatinous, shell-less eggs laid in water or moist environments.[1][2] | Amniotic eggs with a leathery or hard shell, laid on land.[1][2] |
| Development | Undergo metamorphosis from a larval stage (e.g., tadpole) to adult form.[2] | Hatch as smaller versions of adults; no larval stage.[2] |
| Fertilization | Primarily external. | Internal. |
| Habitat | Require habitats near water to keep skin moist and for reproduction.[2] | Can live in a wider range of environments, including dry and arid regions.[2] |
| Heart Structure | Three-chambered heart (two atria, one ventricle). | Most have a three-chambered heart with a partially divided ventricle; crocodilians have a four-chambered heart. |
Skin and Body Covering
One of the most apparent distinctions between the two groups is their skin. Reptiles possess dry, scaly skin.[1][2] These scales, made of keratin, create a waterproof barrier that prevents water loss and provides protection, enabling survival in arid climates.[2] In contrast, amphibians have smooth, moist skin that lacks scales.[1][3] Their skin is permeable, allowing for cutaneous respiration, or the absorption of oxygen directly through the skin. This characteristic makes amphibians highly sensitive to environmental pollutants and requires them to live in or near water to prevent dehydration.[1][2][3]
Reproduction and Development
Reproductive strategies differ significantly between amphibians and reptiles. Amphibians typically lay their jelly-like, shell-less eggs in water.[1][2] These eggs hatch into aquatic larvae, such as the tadpoles of frogs, which breathe through gills. These larvae undergo metamorphosis to develop into their adult form.[2]
Reptiles, however, evolved the amniotic egg, which was a key adaptation for life on land. These eggs have a protective, leathery, or hard outer shell that prevents them from drying out, allowing them to be laid on land.[1] The embryo develops within the self-contained aquatic environment of the egg and hatches as a morphologically mature, miniature version of the adult, bypassing a larval stage. Fertilization is internal in reptiles, whereas it is typically external in amphibians.
Respiration and Other Physiological Differences
Adult amphibians primarily use lungs for breathing but also rely heavily on their porous skin for gas exchange.[3] Their larval forms breathe entirely through gills. Reptiles, on the other hand, breathe exclusively through more complex lungs throughout their entire lives.[3] This more efficient respiratory system supports a more active terrestrial lifestyle. While both groups are generally ectothermic, their methods of thermoregulation can differ. Reptiles are well-known for basking in the sun to absorb heat, while amphibians often avoid direct sun to prevent their skin from drying out.
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 "sheddaquarium.org". Retrieved November 27, 2025.
- ↑ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 "reconnectwithnature.org". Retrieved November 27, 2025.
- ↑ 3.0 3.1 3.2 3.3 3.4 3.5 3.6 "biologicaldiversity.org". Retrieved November 27, 2025.
- ↑ "pressbooks.pub". Retrieved November 27, 2025.
- ↑ "study.com". Retrieved November 27, 2025.
